Underground Oil Pipelines Research Articles

Temporal changes in soil physical properties following reclamation of underground natural gas pipeline rights-of-way on cropland

Underground oil and natural gas pipeline rights-of-way (ROWs) sometimes traverse croplands, leaving behind tracts of disturbed land characterized by poor productivity even after reclamation. This study investigated temporal post-reclamation changes in soil penetration resistance (PR), field saturated hydraulic conductivity (Kfs), near-saturated hydraulic conductivity (KΨ), soil pore indices, and wet aggregate stability (WAS) on natural gas pipeline ROWs on cropland. These attributes were measured in two fields in late summer of 2021 and 2022. Across the two fields, three ROWs that had been reclaimed four to thirteen years prior (i.e., time since reclamation (TSR) of 4 to 13 yr) were assessed along with adjacent undisturbed (off-ROW) transects located 50 m from the ROWs. Measurement locations on each ROW and on off-ROW were 25 m apart. Samples for WAS were collected from the 0–15 cm layer. The results showed a significant (p < 0.05) TSR by soil depth interaction for PR. Treatments were not significantly different in the 0- to 20-cm and 40- to 60-cm layers, but in the 20- to 40-cm depth interval, PR was 57.7–64.2 % greater on the 4.5-yr ROW than on off-ROW. Saturated hydraulic conductivity was three to four times lower on the 4.5- and 6.5-yr ROWs than on the off-ROW. Near-saturated hydraulic conductivity on the 4.5-yr ROW was 61.6 % lower than that on the off-ROW, while no significant differences were detected between the 6.5-yr and 12.5-yr ROWs and the off-ROW. Effective water conductive macroporosity was 72.5 % lower on the 4.5-yr ROW than on the off-ROW. All measured physical properties improved with increasing TSR. These results indicate a significant but slow recovery in soil physical attributes with increasing TSR of ROWs on cropland. This has implications on the productivity of these ROWs as crop yields, which depend on these soil physical properties, are also expected to recover slowly.

Use of fibre optic systems for detection of small leaks on trunk pipelines

This paper is devoted to the issue of efficiency of application of fibre optic leak detection systems for identification of small leaks on trunk pipelines. The main methods of leak detection currently in use have been considered, and parametric and fibre optic LDS have been selected for comparative analysis. In the course of the research a model of product leakage from an underground oil pipeline equipped with a fibre-optic LDS was built in the COMSOL Multiphysics software package. The result of the simulation was the estimated time of leak identification by the fibre-optic system, which turned out to be much shorter than that of the parametric LDS. Compensable environmental damage for each type of system was then calculated, confirming the effectiveness of fibre optic LDS for detecting small leaks on trunk pipelines due to the significant reduction in compensable damage.

Versatile ionic liquid gels formed by dynamic covalent bonding and microphase separated structures.

It is challenging for ionic liquid gels to achieve the combination of rapid self-healing with high toughness. Here, ionic liquid gels (DI-PR) were prepared from readily available materials. A dynamic covalently bonded oxime-carbamate was prepared from polycaprolactone diol, isophorone diisocyanate and dimethylethyleneglyoxime, followed by addition of the "rigid-flexible" cross-linking agent rutin to chemically cross-link the polymer chains and afford the ionic liquid gels, DI-PR. The tensile strength, elongation at break and toughness of the DI-PR gels were as high as 16.5 MPa, 1132.6%, and 52.6 MJ m-3, respectively. The toughness is similar to that of natural silkworm silk (70 MJ m-3) and wool (60 MJ m-3). After stretching, the DI-PR can rebound within 1 s, their room temperature self-healing rate is as high as 92%, they remain functional over the temperature range -50 °C to 140 °C and the interface with a steel plate has an adhesion toughness of >2000 J m-2. These properties mean that the DI-PR gels are particularly suitable for use as anticorrosion coatings for submarine and underground gas and oil pipelines. The use of rutin, which combines rigid quercetin-based structural units with flexible glycoside-based structural units, as a cross-linking agent, provides a new method for improving the toughness of soft materials through its synergistic interaction with hard and soft chain fragments of polyurethanes.

Thermal Diffusivity in the Subsoil: A Case Study in the Asturias (Northern Spain)

This study presents a novel methodology for determining the apparent thermal diffusivity of subsoil in situ, employing two heat transfer models within the subsurface: one method is based on heat conduction caused by air temperature oscillations, while the other considers heat transmission via both conduction and convection due to groundwater flow. Differential equations were solved, and non-linear regression analysis was employed. This method has direct applications in various engineering and environmental domains, such as underground transmission lines, oil and gas pipelines, radioactive waste management, and geothermal systems, especially in the context of implementing horizontal geothermal collectors (HGC). The apparent thermal diffusivity value of 1.514 × 10−6 m2 s−1, within a 95% confidence interval spanning 1.512 × 10−6 m2 s−1 and 1.516 × 10−6 m2 s−1, was obtained from the section between 1.67 and 3.86 m depth in a research borehole located in Asturias, Northern Spain, using twenty-one temperature sensors. The method allowed for the calculation of the subsoil’s apparent thermal diffusivity up to a depth of 14.55 m.

Fully 3D-printed tortoise-like soft mobile robot with muti-scenarios adaptability.

Soft robotic systems are well suited to unstructured, dynamic tasks and environments, owing to their ability to adapt and conform without damaging themselves or their surroundings. These abilities are crucial in areas such as human-robot interaction，simplification of control system and weight reduction. However, as the requirements increase, the drawbacks of existing soft mobile robots such as single locomotion mode and application scenarios, manufacturing difficulties and low energy conversion efficiency gradually emerge.&#xD;Based on the current shortcomings of soft robots, this paper designs and proposes a fully 3D-printed tortoise-like soft mobile robot with muti-scenarios adaptability. The robot uses a Bionic Tortoise Leg Actuator structure that enables simultaneous bending of the actuator in both directions, simplifying robot control and increasing the maximum bending angle achievable. In addition, a reconfiguration design solution has been proposed to enable the robot to implement two bionic modes for land and sea tortoises, adapting to move on hard and soft surfaces and in water, enabling it to move in amphibious and complex environments. The performance of the pneumatic soft actuators are also improved by an improved Digital Light Processing method that enhances the maximum strain of the 3D printed soft material.&#xD;The prototype was tested to give maximum movement speeds for different gaits and environments, demonstrating that the fully 3D printed turtle-like soft-mobile robot designed in this paper is highly adaptable to multiple scenarios. The robot studied in this paper has a wide range of applications, with potential applications including navigation in a variety of domain environments, inspection of large underground oil and gas pipelines, and navigation in high temperature, high humidity and strong magnetic field environments or in military alert conditions.&#xD.

Lawfare in America: A Commentary on the Standing Rock Sioux

ABSTRACT Renewed emphasis by the executive branch regarding the value of indigenous knowledge in government policy hints at the long historical trajectory of eliding native perspectives in American federal planning. Even liberal democracies can marginalize social groups through the enforcement or threat of enforcement of laws. Rules-based societies therefore can exercise disproportionate command through the application of laws in which sanctions are attached to noncompliance. This article follows Charles Dunlap’s definition of lawfare, where laws are applied, or misapplied, as a substitute for military action in order to achieve an operational objective. Lawfare so defined is a valuable lens through which to view the Standing Rock Sioux protest against the Dakota Access Pipeline, a more than 1000 mile long underground oil pipeline from North Dakota to Illinois. This protest was effectively criminalized and dissent met with sanctions including incarceration. The case illustrates the fragility of rights when the law is applied to achieve operational objectives.

Migration behaviour of LNAPL in fractures filled with porous media: Laboratory experiments and numerical simulations

With the increasing requirement of maintaining world energy security and strategic reserves, oil storage and transportation facilities are being built at a large scale. Taking the safe and efficient operation of petroleum storage projects as the goal, a set of experimental apparatus to investigate the migration of contaminants in fractures filled with media was developed to predict and evaluate the environmental risk of oil contaminants leakage. A multiphase numerical flow model based on COMSOL was built based on the laboratory experimental model. Specifically, the migration behaviour of Light Non-aqueous Phase Liquid (LNAPL) through a sand-filled fractured medium was studied by laboratory experiments and numerical simulations. Image and chemical analyses methods were used to monitor and study LNAPL migration behaviour for varying grain sizes of porous medium filling the fractures and varying groundwater table elevations. Laboratory experimental results showed that the LNAPL migration velocity in filled fracture network was significantly faster than that in adjoining porous media during the initial stage of infiltration. The migration velocity increased with the relative permeability of filled sand, which was closely related to the Van Genuchten (VG) model parameters α and n. LNAPL migrated downward with the falling groundwater table and became entrapped with the rising groundwater table, and the amount of entrapment depended on VG model parameters. Hydrogeological parameters were calibrated and LNAPL migration in filled fractured media was predicted using the calibrated numerical model. Simulation results revealed that fracture inclination had an important influence on LNAPL migration in filled fractured media and its migration velocity decreased with a decrease in fracture inclination. These research results can be applied to the control and remediation of oil-contaminated sites in fractured rock settings, such as at underground oil storage tanks and caverns, as well as at underground oil pipelines.

Preparation of PFDTS-kaolin/PU superamphiphobic coatings with antibacterial, antifouling and improved durability property

Superamphiphobic materials have a higher and broader application value compared to superhydrophobic materials. Nevertheless, durability has always been an obstacle to its practical application. Herein, we report a method that utilizes 1H, 1H, 2H, 2H-perfluorodecyltrichlorosilane (PFDTS) as an esterification reaction modifier agent for kaolin, and polyurethane as adhesive binding to substrates, so as to construct inorganic/polymer composite coatings, for obtaining a durability superamphiphobic material. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy characterization reveal that kaolin is successfully grafted by PFDTS. Thermogravimetry and differential scanning calorimetry tests exhibit that the material can withstand temperatures up to 400 °C. The self-cleaning test demonstrates that the as-prepared coating is repulsive to a variety of liquids such as water, milk, mud, olive oil, and n-hexadecane, which has a surface tension as low as 27.5 mN/m. It still maintains superamphiphobicity after the material is polished by sandpaper and the retention rate is above 96 % when the friction distance is about 4500 cm. After soaking in strong acid and strong base, it shows superior acid resistance and favorable alkali resistance. After aging durability irradiation for 300 min, it still retains superamphiphobicity. In addition, the biological contamination resistance tests indicate that it has a certain adhesion resistance to gram-positive bacteria Staphylococcus aureus and gram-negative bacteria Escherichia coli. Therefore, it is a promising kind of durable anti-fouling material for underground oil pipelines and construction.

Increasing the efficiency of microbiological protection of underground facilities

Highlight important aspects of microbiological protection of underground facilities. It is shown that an important environmental and technological problem is the protection of underground oil and gas pipelines from microbial corrosion by soil corrosion-hazardous microorganisms, including the crucial role played by sulfatvosstanovitelnye (SRB) and thione (TB) bacteria. The influence of the nature of the inhibitor and the hydrophobicity of the electrolyte composition of basic and modified mastics. The influence of heterotrophic bacteria isolated from the damaged asphalt blocks pipeline, the stability of modified bitumen-polymer sealant. The effect of nitrogen-containing corrosion inhibitors on the growth and enzyme activity of the bacteria and the sulfur cycle, the mechanism locks thiobacteria and gidrogenaznoi reaction korozionnoaktivnih SRB. The efficiency of the derivatives dioksodekagidroakridina the rate of microbial corrosion of steel under the ISF and thiobacteria. A comparative evaluation of the effectiveness of these inhibitors in industrial inhibitor. These inhibitors provide a high degree of protection from corrosion in the presence of SRB (90%), which indicates their antibacterial properties and offers the prospect of their use in industrial applications of anaerobic corrosion caused by SRB. Keywords: temperature measurements; measurement error; thermal energy; thermodynamics; metrology.

Application of GPR System With Convolutional Neural Network Algorithm Based on Attention Mechanism to Oil Pipeline Leakage Detection

High-efficiency and high-quality detection of oil pipeline will significantly reduce environmental pollution and economic loss, so an unconventional oil pipeline anomaly detection convolutional neural network (CNN) algorithm based on attention mechanism is proposed in this article. By taking the simulated ground-penetrating radar (GPR) data as prior knowledge, the structure of the convolutional neural network based on the attention mechanism is constructed, and finally, the location and working condition of the underground oil pipeline are recognized in the simulation data and measured data. The simulation results show that after using the new optimized convolutional neural network, the accuracy rates of the leakage discrimination from horizontal data acquired along the oil pipeline and the classification of the target from longitudinal data acquired perpendicular to the oil pipeline are 94.5% and 84.6%, respectively. Compared with the original convolutional neural network without an attention mechanism, the accuracy rates of the leakage discrimination and the classification of the target are improved by 6.2% and 7.8%, respectively. We further train measured data with an optimized convolutional neural network, results show that compared with a conventional network, the new network can increase the corresponding accuracy rates of the leakage discrimination and the targets classification by 5.4% and 6.9%, reaching 92.3% and 84.4%, respectively. According to our study, the ground-penetrating radar oil pipeline recognition algorithm based on an attention mechanism can well accomplish the identification of underground oil pipelines.

Parametric vibrations of the underground oil pipeline

This paper is devoted to obtaining a solution to the problem of parametric vibrations and dynamic stability of thin-walled underground oil pipelines, taking into account the effect of a damper. An equation has been obtained that allows estimating the dynamic stability of underground oil pipelines, which consists in constructing regions on the plane of the parameters ωmn, ω0 and the longitudinal force parameter P, as well as the internal pressure p0, where ωmn is the frequency of free vibrations, ω0 is the excitation frequency. The assessment of the dynamic stability of the oil pipeline section is made for the known values of ωmn, ω0, p0, P, k by finding a point. If the point does not fall into the outlined area, it means that dynamic stability is ensured, otherwise there is a danger of parametric resonance.

Hydrodynamic model of a funnel from an explosion of a buried charge

The problems of the flow of an ideal fluid with an unknown (free) boundary is known from the theory of jets, which is well developed and widely used to solve problems in the field of hydrodynamics and filtration theory. The methods of this theory can also be successfully applied to calculate the shape of craters during explosions, using the well-developed mathematical apparatus of the theory of potential flows and the theory of analytical functions. One of the main tasks that arise when using ejection explosions is the task of determining the size and shape of the ejection funnels depending on the geometry of the area, soil properties, energy characteristics of the charge, as well as its shape and location. Explosions are used in the development of minerals, in the excavation of trenches including for laying underground oil and gas pipelines in hard rocks, in the construction of dams, the construction of underground storage facilities, including gas. Camouflage explosions are used in the oil and gas industry for creating underground storage facilities and intensifying oil and gas production. The scope of the explosion in the national economy is constantly expanding. The aim of the work is the analytical construction of an accurate mapping of the area of the complex potential on the plane of the hodograph, which implements the task of ejecting soil during the explosion of a corded (elongated) buried charge. The paper uses a solid-liquid explosion model proposed by M. A. Lavrentiev in the middle of the 20th century. Within the framework of this mathematical model, a solution for the problem is obtained and analyzed in detail: the explosion of a point buried charge. The choice of this problem is due to the fact that it has an exact analytical solution, and in a simple analytical form, in elementary functions. The solution of this problem was known from literary sources, but it was solved anew in a different way.

Мониторинг изменения состояния растительного покрова на участке трассы трубопровода проекта «Сахалин-2» по данным космических съемок

The construction of underground main oil and gas pipelines leads to significant changes in natural landscapes. During the construction of main pipelines, felling of forest massifs is carried out. There is a high probability of the development of exogenous geological processes in the presence of mountain-ous relief and abundant precipitation. Revegetation control of pipelines is very important, and special attention should be paid to control when laying pipelines through specially protected natural areas. The article presents the results of assessing the nature and dynamics of the restoration of the vegetation cover on the section of the Sakhalin-2 gas pipeline in the Dolinsky sanctuary based on the results of calculating NDVI from satellite images using geoinformation technologies, and checking the results by field research data. The purpose of the research is to analyze the change in the state of the vegetation cover, determined by the volume of phytomass (calculation by NDVI) based on space monitoring da-ta. Methods: interpretation and analysis of space images from spacecraft of the Landsat and Sentinel-2 family for the period from 2001 to 2021, geoinformation mapping of changes in the state of vegetation on the ArcGIS platform. Results: 5 stages of change in the state of the vegetation cover in the studied time interval were identified. The results show revegetation 10 years after the completion of the pipeline. Good restoration of valley forests and grass cover was noted. Sparse vegetation is com-mon in sections of the pipeline where biological reclamation has not been carried out. As result of work carried out, an increase in NDVI revealed, and, consequently, the presence of good conditions for the growth of plant communities, typical for the investigated section of the pipeline of the Sakhalin-2 project after completion of construction work.

Influence of snow cover on temperature field of frozen ground

Research on the effect of snow on the temperature field of frozen ground is of great significance to the laying of underground oil pipelines, design of roads, and control of frost damage in cold regions. The heat transport laws of frozen ground with phase changes under periodic temperature boundary conditions were analyzed based on data monitoring in this paper. Based on the boundary conditions determined by the monitoring data, the numerical calculations of frozen ground and subgrade with/without snow cover were carried out, and the effects of snow cover on the temperature fields of frozen ground and subgrade in cold regions were explored. Monitoring results demonstrate that the temperature at different sections of frozen ground with phase change presents a sine-like function under the periodic temperature boundary condition. According to monitoring data, when the thickness of the natural surface snow cover is about 25 cm, the daily average minimum temperature of soil at 0.1 m from the surface will rise by about 10 °C compared to that without snow cover during a year (in a cycle); nevertheless, when combined with numerical calculation, the permafrost table increases by about 2.87 m, and the permafrost base decreases by more than 5.59 m. Under the boundary conditions set in this paper, the permafrost under the subgrade disappears in a greater area due to the construction of the subgrade in the snow-covered area. In addition, the elliptical thawing soil area produced by the lower part of the slope of a snow-covered subgrade will adversely affect its stability.

Influence of Biochar Particle Size Fractions on Thermal and Mechanical Properties of Biochar-Amended Soil

Thermal backfill is essential for projects such as underground crude oil pipelines and crude oil storage tanks to control the heat migration from the source. The properties of locally available soil may not be adequate as thermal backfill and hence need suitable amendment. Biochar is a low thermal conductive material and may contribute to an increase in soil strength. There are no such studies that deal with the thermal properties of biochar-based backfill. Further, the influence of biochar particle size fractions on soil thermal properties has not been reported until now. Therefore, the possibility of biochar as a soil amendment for modifying thermal backfill characteristics is explored in this study. Two types of soils (highly plastic silt and clayey sand) are amended with three biochar content amounts (5%, 10%, and 15%), and three different particle size fractions [coarse (4.7–2 mm), medium (2–0.425 mm), and fine (0.425–0.075 mm)], and their compaction characteristics as well as thermal and mechanical properties are investigated. It was observed that the amendment of biochar in soil reduced the thermal and mechanical properties of the soil. Further, the reduction in soil thermal conductivity and volumetric heat capacity with biochar amendment was more in coarser biochar fraction than finer and medium fractions. In comparison, reduction in unconfined compressive strength (UCS) was more in finer biochar fraction. Additionally, the thermal properties reduction was higher in clayey sand than highly plastic silt. An inverse linear correlation of thermal conductivity with pH and electrical conductivity were observed for both soil biochar mixes. The relationship between the thermal properties and UCS indicates that the medium fraction biochar provides the optimized value for reducing thermal properties and UCS of biochar amended soil (BAS). This proves the efficacy of BAS as thermal backfill.

Simulation modeling of non-stationary thermophysical processes when monitoring the reliability of main oil pipelines in the Arctic

The use of modern complexes for calculating the designed pipeline systems and for predicting their behavior for a period of more than ten years is necessary in modern conditions of the constantly developing hydrocarbon market and the development of new northern territories for greater oil production. It will allow avoiding accidents and environmental disasters that have become more frequent in recent years due to the deterioration of existing equipment. The article presents a method for monitoring the main reliability parameters of underground oil pipelines, taking into account changes in soil foundations, mainly in the Arctic zone of the Russian Federation. An oil pipeline section is considered as an object for monitoring of heat engineering processes and their influence on the reliability of the system. We describe the main results of calculations of the oil pipeline section and simulate changes in soil foundations. We used a multilayer pipe with polyurethane foam insulation and coating for the calculations to improve the reliability characteristics. This pipe has showed the best results of modeling in comparison with the design pipe.

An extension approach to estimate soil corrosivity for buried pipelines

Underground oil and gas pipelines are usually expected to be long-lasting. Corrosion of these steel pipelines may cause structural failures that significantly threaten life and cause environmental hazards. Therefore, developing a reliable approach to estimate soil corrosivity is important for designing a targeted anti-corrosion structure and performing risk assessment. In this study, an extension-based approach is proposed to evaluate soil corrosivity based on the following seven soil properties: redox potential, soil resistivity, pH, pipe-to-soil potential, water content, Chloride (Cl−) concentration, and salt content. Specifically, the soil was classified into five corrosivity levels, and the classic domain element, joint domain element, and element to be evaluated were established by the matter-element theory. Then, the corrosivity level was determined based on the maximum correlation degree of the multi-index to the five levels, and the final classification was obtained from the eigenvalues of the grade variables. Finally, the case study was examined to validate the application of the approach, and the results were compared to the method of buried metal specimens, which was used as a criterion. The present approach, which provided a more detailed classification, was demonstrated to be a superior choice for classifying soil corrosivity levels.

Optimization of insulation thickness and emissions rate reduction during pipeline carrying hot oil

The present study discusses the insulation thickness effects on the underground oil pipeline life cycle overall costs and its sensitivity to economic parameters and environmental Emissions. The heating degree-day and life cycle cost procedures are used for the optimization and environmental analyses of the mazut oil pipeline. The insulation materials used are Rock wool, PF, and EPS regarding all the physical and economical parameters of insulation thickness. The results show that the optimum insulation thickness varies between 70.7 and 130.4 mm, the annual energy saving cost varies between 403.69 and 419.29 $/m, the payback periods vary between 0.331 and 0.887 years, the reductions in emissions at optimum insulation thickness marked 90.84% for Rock wool,93.2% for PF, and 93.28% for EPS. Both lifetime and the unit cost of insulation is sensitive to the insulation thickness. Additionally, the increased discount rate and cost of insulation material per unit volume reduce the optimum insulation thickness. In conclusion, it is predictable that this research can supply a guide for engineers as insulation is used to decrease the total energy loss and total annual cost, which includes the fuel and insulation expenses of the pipeline of large diameters that are used to transmit viscous oil.

Trenchless Construction Technologies for Oil and Gas Pipelines: State-of-the-Art Review

AbstractWith the accelerated construction and aging of underground oil and gas pipelines, trenchless technology (TT) has developed rapidly in recent years. This paper briefly introduces the trenchl...

Определение эффективного радиуса действия вертикального заземлителя в условиях экранирования катодного тока подземных нефтегазопроводов площадных объектов

Определение эффективного радиуса действия вертикального заземлителя в условиях экранирования катодного тока подземных нефтегазопроводов площадных объектов